Javascript 在所有屏幕中反应本机传递数据
我希望能够访问所有屏幕中的对象。我通过firebase返回的用户对象。我从方法onAuthStateChanged中获得obejct。如何在app.js中获取用户并在所有屏幕中访问它 这是根应用程序中的代码:Javascript 在所有屏幕中反应本机传递数据,javascript,firebase,react-native,firebase-authentication,Javascript,Firebase,React Native,Firebase Authentication,我希望能够访问所有屏幕中的对象。我通过firebase返回的用户对象。我从方法onAuthStateChanged中获得obejct。如何在app.js中获取用户并在所有屏幕中访问它 这是根应用程序中的代码: import React, { useEffect, useState } from 'react'; import { SafeAreaView, View, ActivityIndicator } from 'react-native'; import { createDrawerNa
import React, { useEffect, useState } from 'react';
import { SafeAreaView, View, ActivityIndicator } from 'react-native';
import { createDrawerNavigator } from '@react-navigation/drawer';
import { NavigationContainer } from '@react-navigation/native';
import AsyncStorage from '@react-native-community/async-storage';
import { globalStyles, styles } from './styles/global';
import BottomTabScreen, { RootStackScreen } from './navigation/Index';
import DrawerContent from './navigation/DrawerContent';
import { on_auth_state_changed } from './firebase/Api';
const Drawer = createDrawerNavigator();
export default function App() {
const [authState, setAuthState] = useState({
isAuthenticated: false,
isAuthenticationReady: false,
isLoadingComplete: false,
});
useEffect(() => {
on_auth_state_changed(authStateChanged);
}, [])
function authStateChanged(user) {
setAuthState({
...authState,
isAuthenticated: !!user,
isAuthenticationReady: true,
isLoadingComplete: true,
})
}
if (!authState.isLoadingComplete) {
return (
<View style={{ flex: 1, justifyContent: 'center', alignItems: 'center', backgroundColor: '#80c904' }}>
<ActivityIndicator size="large" />
</View>
);
}
return (
<SafeAreaView style={globalStyles.container}>
<NavigationContainer>
{(authState.isAuthenticated) ?
<Drawer.Navigator drawerContent={props => <DrawerContent {...props} />}>
<Drawer.Screen name="HomeDrawer" component={BottomTabScreen} />
</Drawer.Navigator>
:
<RootStackScreen />
}
</NavigationContainer>
</SafeAreaView>
);
}
import React,{useffect,useState}来自“React”;
从“react native”导入{SafeAreaView,View,ActivityIndicator};
从'@react导航/drawer'导入{createDrawerNavigator};
从'@react-navigation/native'导入{NavigationContainer};
从“@react native community/async storage”导入异步存储;
从“./styles/global”导入{globalStyles,styles};
从“./navigation/Index”导入BottomTabScreen,{RootStackScreen};
从“./navigation/DrawerContent”导入抽屉内容;
从“./firebase/Api”导入{on_auth_state_changed};
const Drawer=createDrawerNavigator();
导出默认函数App(){
常量[authState,setAuthState]=useState({
I认证:错误,
isAuthenticationReady:false,
isLoadingComplete:false,
});
useffect(()=>{
on_auth_state_changed(authStateChanged);
}, [])
函数authStateChanged(用户){
setAuthState({
…国家,
已验证:!!用户,
isAuthenticationReady:正确,
isLoadingComplete:正确,
})
}
如果(!authState.isLoadingComplete){
返回(
);
}
返回(
{(authState.isAuthenticated)?
}>
:
}
);
}
您可以使用。还有其他选项,如Redux或任何状态管理库,但对于您的需要,上下文API已经足够了